How Batteries Get Wrecked and What To Do About It


So far in this Online Book we have covered the basic theory. Now let's look at, and quantify, what will happen if we just stick with the electrical system installed on most boats. After all, if we are going to improve things, it's as well to know what the payoff will be. About eight years ago, we switched to Absorbed Glass Mat (AGM) batteries on Morgan’s Cloud, to get the following benefits over liquid filled lead-acid batteries:
  • Shorter recharge times since AGM batteries accept a faster charge rate.
  • About 10% more capacity in the same size battery.
However, our experience was not good: We went through four sets of house batteries from two different manufacturers. In the process of solving that problem, we learnt a huge amount that can be applied to the care of any lead acid battery. Read on:

John was born and brought up in Bermuda and started sailing as a child, racing locally and offshore before turning to cruising. He has sailed over 100,000 miles, most of it on his McCurdy & Rhodes 56, Morgan's Cloud, including eight ocean races to Bermuda, culminating in winning his class twice in the Newport Bermuda Race. He has skippered a series of voyages in the North Atlantic, the majority of which have been to the high latitudes. John has been helping others go voyaging by sharing his experience for twenty years, first in yachting magazines and, for the last 18 years, as co-editor/publisher of AAC.

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